Effect of Humic Acid Application on Some Physiological Characteristics of Miniature Rose (Rosa chinensis var. minima  Baby Masquerade')

This experiment was conducted to investigate the positive effects of foliar and soil application of humic acid on chlorophyll content, flower longevity, antioxidant enzymes activity, proline, malondialdehyde and protein content in a completely randomized design with two factors: humic acid at 4 concentrations (0, 500, 1000 and 2000 ppm) and 2 application method of humic acid (foliar spray and drench) with 3 replications and 2 observations in Rosa chinensis ‘Baby Masqurade’. The results showed that both soil and foliar applications of humic acid caused to increase chlorophyll and protein content, antioxidant enzymes activities and flower longevity respectively about to 2, 5, 3 and 1.75 fold compared to control. MDA levels were increased in soil treatments with increasing concentrations of humic acid but inversely were decreased in foliar treatments. This process is repeated in the activity of APX enzyme. Catalase activity was increased in low concentrations of humic acid but with increasing concentration, its activity was declined. The total protein was increased in all of the humic acid concentrations (except in 500mg/l HA as soil application) compared to control. The results of this experiment showed that foliar and soil application of humic acid with increasing the activity of antioxidant enzymes and chlorophyll and protein content of plant cause to increase the longevity of flowers.